Before this, I had never considered all of the unknowable sounds in the world. Sounds we could only see graphed or measured. The deep sounds of the Earth that no one hears. The eruption of volcanic vents thousands of metres below the water. The scraping of icebergs along the ocean floor. The mysterious bursts and burbles of the Earth that even science couldn’t fully explain. The skyquakes that boom like cannons on calm summer days over the Bay of Fundy, or cause kitchen plates to rattle on Lough Neagh in Ireland. Or the gas escaping from vents, from vegetation rotting at the bottom of lakes or released from limestone decaying in underwater caves; the explosive and volatile digestive system of the Earth, bubbling, burping, expelling. The concussing of continental shelf fragments calving off into the Atlantic abyss. The roars from solar winds. From magnetic activity. From avalanches. From distant thunder that, through some anomaly in the upper atmosphere, managed to throw its voice across valleys, across mountain ranges to different cities and different states.

Before this, sound was something I took for granted. It was always there, providing pleasant texture and useful information to my day-to-day life. I liked music, but I have never been an aficionado like Paul. I could never tell the difference between the sound quality of a CD and a record. But once this all began, all I could think about was sound. And not just my sound—for I came to think of it as ‘my sound,’ as if I owned it, or it owned me—but the mysterious dimensions of sound more generally.

One night, after Paul had already gone upstairs to bed, I was sitting with my laptop in the dark of the living room. I googled ‘most beautiful sound in the world,’ and spent an hour listening to frogs singing in a Malaysian swamp, the cascades of the Neretva River, the chirruping of thrushes at dawn, the wind whipping itself against an ocean cliffside in Sonoma. But when I thought of it, the most beautiful sound I had probably ever heard was a lawn mower. When I was a girl, lying in the hot summer grass of my grandma’s bungalow, listening to the sound of her neighbour cutting his lawn in the distance, I remember feeling like I would live forever. The purr of that lawn mower, three or four houses over, was like the sound of eternity itself. Sitting there in the living room, it occurred to me—the entire story of my life could be told through the sounds that have surrounded it. A continuous forty-year playback. A biography of room tones, bird calls, pop songs, voice messages, laughter, train whistles, dog barks, and wind moving through innumerable leaves.